The present application relates to solid-state thin-film battery technology. More particularly, the present application relates to fast charging, high capacity, solid-state battery structures, and methods of forming the same.
In recent years, there has been an increased demand for portable electronic devices such as, for example, computers, mobile phones, tracking systems, scanners, medical devices, smart watches, and fitness devices. One drawback with portable electronic devices is the need to include a power supply within the device itself. Typically, a battery is used as the power supply of such portable electronic devices. Batteries must have sufficient capacity to power the portable electronic device for at least the length that the device is being used. Sufficient battery capacity can result in a power supply that is quite heavy and/or large compared to the rest of the portable electronic device. As such, smaller sized and lighter weight power supplies with sufficient energy storage are desired. Such power supplies can be implemented in smaller and lighter weight portable electronic devices.
Another drawback of conventional batteries is that some of the batteries contain potentially flammable and toxic materials that may leak and may be subject to governmental regulations. As such, it is desired to provide an electrical power supply that is safe, solid-state and rechargeable over many charge/discharge life cycles.
One type of an energy-storage device that is small and light weight, contains non-toxic materials and that can be recharged over many charge/discharge cycles is a solid-state, lithium-based battery. Lithium-based batteries are rechargeable batteries that include two electrodes implementing lithium.
The charging speed of solid-state, lithium-based batteries is often limited and is typically below 3 C, wherein C is the total battery capacity per hour. Some factors that may contribute to the limited charging speed of solid-state, lithium-based batteries is the presence of a high resistive cathode material such as, for example, LiCoO2, within the battery cell material stack, the high interfacial energy that can exist between metallic lithium and the top electrode, and metallic-lithium dendrite formation under large voltage bias.
There is thus a need for providing solid-state battery structures, such as lithium-based battery structures, that are fast charging, yet have a high capacity.